Cypridina hilgendorfii is a marine ostracod crustacean living in the coast of the Sea of Japan, which releases a pale blue luminescent fluid when it is disturbed. The luminescence is produced by the oxidation of luciferin by an enzyme luciferase. The application of this luminescent system to the assay of a component contained in a sample in a trace amount is expected.
However, although luciferin can be chemically synthesized in a large amount, luciferase cannot be chemically synthesized because it is an enzyme, so that it is difficult to obtain luciferase in a large amount. This situation is also true in the case of luciferase of Cypridina hilgendorfii and highly purified luciferase of Cypridina hilgendorfii has not yet been obtained. Further, because of sea pollution, the catch of Cypridina hilgendorfii has drastically decreased. Thus, the constant supply of the luciferase of Cypridina hilgendorfii is not assured. Therefore, it is desired to establish a large scale production process of the enzyme, which employs the genetic recombination technique.
The object of the present invention is to attain the synthesis of highly purified luciferase by chemical synthesis process or by genetic recombination process, to provide a gene encoding the protein, to attain the expression of the cloned gene in an animal cell, yeast cell, in E. coli cell or the like, and to produce the highly purified enzyme in a large amount using the cell.